Hancockiamide D is the major component of an unusual 2,5-disubstituted piperazine from the Australian soil fungus Aspergillus hancockii. Hancockiamide D is the parent piperazine of the cinnamoylated hancockiamides A to C. Hancockiamide D displays potent and selective cytotoxic activity and is inactive against neonatal foreskin fibroblasts. The producing organism, A. hancockii, has the capacity to degrade cellulose, hemicellulose, lignin, pectin, starch, chitin, cutin and fructan as nutrient sources.